Stable Isotope Probing of Microorganisms in Environmental Samples with H218O
We describe a protocol for investigating microbial growth in environmental samples via stable isotope probing (SIP) with H218O. Water is a universal substrate for all microorganisms and replication is required for DNA to become labeled with 18O. By measuring how much the DNA of each taxon becomes enriched with 18O when an environmental sample is incubated with H218O, it is feasible to quantify that population’s DNA replication rate, which is a proxy for growth.
Key wordsStable isotope probing H218O Microbial growth
This research was supported by the National Science Foundation (NSF DEB-1241094) and the Department of Energy’s Biological Systems Science Division, Program in Genomic Science (DE-SC0010579 and DE-SC0016207).